1,674 research outputs found
Apparent Diffusion Coefficient for Distinguishing Between Malignant and Benign Lesions in the Head and Neck Region: A Systematic Review and Meta-Analysis
Background: The purpose of the present meta-analysis was to provide evident data
about use of apparent diffusion coefficient (ADC) values for distinguishing malignant and
benign lesions in the head and neck region.
Material and Methods: MEDLINE and Scopus databases were screened for
associations between ADC and malignancy/benignancy of head and neck lesions up to
December 2018. Overall, 22 studies met the inclusion criteria. The following data were
extracted: authors, year of publication, study design, number of patients/lesions, lesion
type, mean value, and standard deviation of ADC. The primary endpoint of the systematic
review was the analysis of the association between lesion nature and ADC values. The
methodological quality of the involved studies was checked according to the Quality
Assessment of Diagnostic Accuracy Studies (QUADAS) instrument. The meta-analysis
was undertaken by using RevMan 5.3 software. DerSimonian and Laird random-effects
models with inverse-variance weights were used without further correction to account
for the heterogeneity between the studies. Mean ADC values including 95% confidence
intervals were calculated separately for benign and malignant lesions.
Results: The acquired 22 studies comprised 1,227 lesions. Different malignant lesions
were diagnosed in 818 cases (66.7%) and benign lesions in 409 cases (33.3%). The
mean ADC value of the malignant lesions was 1.04 Ă 10â3 mm2
/s, and the mean value
of the benign lesions was 1.46 Ă 10â3 mm2
/s. Lymphomas and sarcomas showed the
lowest calculated mean ADC values, 0.7 and 0.79 Ă 10â3 mm2
/s, respectively. Adenoid
cystic carcinomas had the highest ADC values (1.5 Ă 10â3 mm2
/s). None of the analyzed
malignant tumors had mean ADC values above 1.75 Ă 10â3 mm2
/s.
Conclusion: ADC values play a limited role in distinguishing between malignant and
benign lesions in the head and neck region. It may be only suggested that lesions with
mean ADC values above 1.75 Ă 10â3 mm2
/s are probably benign. Further large studies
are needed for the analysis of the role of diffusion-weighted imaging (DWI)/ADC in the
discrimination of benign and malignant lesions in the head and neck region
Association Between VEGF Expression and Diffusion Weighted Imaging in Several TumorsâA Systematic Review and Meta-Analysis
To date, only a few studies have investigated relationships between Diffusion-weighted
imaging (DWI) and Vascular endothelial growth factor (VEGF) expression in tumors. The reported
results are contradictory. The aim of the present analysis was to review the published results and
to perform a meta-analysis regarding associations between apparent diffusion coefficients (ADC)
derived from DWI and VEGF expression. MEDLINE library was screened for relationships between
ADC and VEGF expression up to January 2019. Overall, 14 studies with 578 patients were identified.
In 10 studies (71.4%) 3 T scanners were used and in four studies (28.6%) 1.5 T scanners. Furthermore,
seven studies (50%) had a prospective design and seven studies (50%) had a retrospective design.
Most frequently, prostate cancer, followed by rectal cancer, cervical cancer and esophageal cancer were
identified. The pooled correlation coeffcient of all tumors was r = 0.02 [95% CI 0.26â0.21]. ADC
values derived from routinely acquired DWI do not correlate with VEGF expression in various tumors.
Therefore, DWI is not sensitive enough to reflect angiogenesis-related microstructure of tumors
Pulmonary Vessel Obstruction Does Not Correlate with Severity of Pulmonary Embolism
The aim of the present study was to analyze possible relationships between pulmonary
vessel obstruction and clinically relevant parameters and scores in patients with pulmonary embolism
(PE). Overall, 246 patients (48.8% women and 51.2% men) with a mean age of 64.0 17.1 years were
involved in the retrospective study. The following clinical scores were calculated in the patients:
Wells score, Geneva score, and pulmonary embolism severity index (PESI) score. Levels of D-dimer
(g/mL), lactate, pH, troponin, and N-terminal natriuretic peptide (BNP, pg/mL) were acquired.
Thrombotic obstruction of the pulmonary arteries was quantified according to Mastora score. The data
collected were evaluated by means of descriptive statistics. Spearmanâs correlation coeffcient was
used to analyze associations between the investigated parameters. P values < 0.05 were taken
to indicate statistical significance. Mastora score correlated weakly with lactate level and tended
to correlate with D-dimer and BNP levels. No other clinical or serological parameters correlated
significantly with clot burden. Thrombotic obstruction of pulmonary vessels did not correlate with
clinical severity of PE
Diagnostic Benefit of High b-Value Computed Diffusion-Weighted Imaging in Patients with Hepatic Metastasis
Diffusion-weighted imaging (DWI) has rapidly become an essential tool for the detection of malignant liver lesions. The aim of this study was to investigate the usefulness of high b-value computed DWI (c-DWI) in comparison to standard DWI in patients with hepatic metastases. In total, 92 patients with histopathologic confirmed primary tumors with hepatic metastasis were retrospectively analyzed by two readers. DWI was obtained with b-values of 50, 400 and 800 or 1000 s/mm2 on a 1.5 T magnetic resonance imaging (MRI) scanner. C-DWI was calculated with a monoexponential model with high b-values of 1000, 2000, 3000, 4000 and 5000 s/mm2. All c-DWI images with high b-values were compared to the acquired DWI sequence at a b-value of 800 or 1000 s/mm2 in terms of volume, lesion detectability and image quality. In the group of a b-value of 800 from a b-value of 2000 s/mm2, hepatic lesion sizes were significantly smaller than on acquired DWI (metastases lesion sizes b = 800 vs. b 2000 s/mm2: mean 25 cm3 (range 10â60 cm3) vs. mean 17.5 cm3 (range 5â35 cm3), p < 0.01). In the second group at a high b-value of 1500 s/mm2, liver metastases were larger than on c-DWI at higher b-values (b = 1500 vs. b 2000 s/mm2, mean 10 cm3 (range 4â24 cm3) vs. mean 9 cm3 (range 5â19 cm3), p < 0.01). In both groups, there was a clear reduction in lesion detectability at b = 2000 s/mm2, with hepatic metastases being less visible compared to c-DWI images at b = 1500 s/mm2 in at least 80% of all patients. Image quality dropped significantly starting from c-DWI at b = 3000 s/mm2. In both groups, almost all high b-values images at b = 4000 s/mm2 and 5000 s/mm2 were not diagnostic due to poor image quality. High c-DWI b-values up to b = 1500 s/mm2 offer comparable detectability for hepatic metastases compared to standard DWI. Higher b-value images over 2000 s/mm2 lead to a noticeable reduction in imaging quality, which could hamper diagnosis
CT Texture Analysis of Pulmonary Neuroendocrine TumorsâAssociations with Tumor Grading and Proliferation
Texture analysis derived from computed tomography (CT) might be able to provide clinically relevant imaging biomarkers and might be associated with histopathological features in tumors. The present study sought to elucidate the possible associations between texture features derived from CT images with proliferation index Ki-67 and grading in pulmonary neuroendocrine tumors. Overall, 38 patients (n = 22 females, 58%) with a mean age of 60.8 ± 15.2 years were included into this retrospective study. The texture analysis was performed using the free available Mazda software. All tumors were histopathologically confirmed. In discrimination analysis, âS(1,1)SumEntrpâ was significantly different between typical and atypical carcinoids (mean 1.74 ± 0.11 versus 1.79 ± 0.14, p = 0.007). The correlation analysis revealed a moderate positive association between Ki-67 index with the first order parameter kurtosis (r = 0.66, p = 0.001). Several other texture features were associated with the Ki-67 index, the highest correlation coefficient showed âS(4,4)InvDfMomâ (r = 0.59, p = 0.004). Several texture features derived from CT were associated with the proliferation index Ki-67 and might therefore be a valuable novel biomarker in pulmonary neuroendocrine tumors. âSumentrpâ might be a promising parameter to aid in the discrimination between typical and atypical carcinoids
Magnetic Resonance Imaging of Peritoneal Carcinomatosis: Evaluation of High b-Value Computed Diffusion-Weighted Imaging
Over the last few years, diffusion-weighted imaging (DWI) has become increasingly
relevant in the diagnostic assessment of peritoneal carcinomatosis. The aim of this study was
to investigate the benefits of high-b DWI (c-DWI) compared to standard DWI in patients with
peritoneal carcinomatosis. A cohort of 40 patients with peritoneal carcinomatosis were included in
this retrospective study. DWI was performed with b-values of 50, 400, and 800 or 1000 s/mm2 on a
1.5-T magnetic resonance imaging (MRI) scanner. C-DWI was calculated using a mono-exponential
model with high b-values of 1000, 2000, 3000, 4000, and 5000 s/mm2. All c-DWI images with high
b-values were compared in terms of volume, detectability of peritoneal lesions, and image quality
with the DWI sequence acquired with a b-value of 800 or 1000 s/mm2 by two readers. In the group
with a b-value of 800 s/mm2, there was no statistically significant difference in terms of lesion volume.
In the second group with a b-value of 1000 s/mm2, peritoneal carcinomatosis lesions were statistically
significantly larger than in the c-DWI with a- high b-value of 2000 s/mm2 (median 7 cm3, range
1â26 cm3vs. median 6 cm3, range 1â83 cm3, p < 0.05). In both groups, there was a marked decrease
in the detectability of peritoneal lesions starting at b = 2000 s/mm2. In addition, image quality
decreased noticeably from c-DWI at b = 3000 s/mm2. In both groups, all images with high b-values
at b = 4000 s/mm2 and 5000 s/mm2 were not diagnostically valuable due to poor image quality.
The c-DWI technique offers good diagnostic performance without additional scanning time. High
c-DWI b-values up to b = 1000 s/mm2 provide comparable detectability of peritoneal carcinomatosis
compared to standard DWI. Higher b-values over 1500 s/mm2 result in lower image quality, which
might lead to misdiagnosis
CT Texture AnalysisâCorrelations With Histopathology Parameters in Head and Neck Squamous Cell Carcinomas
Introduction: Texture analysis is an emergent imaging technique to quantify heterogeneity in radiological images. It is still unclear whether this technique is capable to reflect tumor microstructure. The present study sought to correlate histopathology parameters with texture features derived from contrast-enhanced CT images in head and neck squamous cell carcinomas (HNSCC).Materials and Methods: Twenty-eight patients with histopathological proven HNSCC were retrospectively analyzed. In every case EGFR, VEGF, Hif1-alpha, Ki67, p53 expression derived from immunhistochemical specimen were semiautomatically calculated. Furthermore, mean cell count was estimated. Texture analysis was performed on contrast-enhanced CT images as a whole lesion measurement. Spearman's correlation analysis was performed, adjusted with Benjamini-Hochberg correction for multiple tests.Results: Several texture features correlated with histopathological parameters. After correction only CT texture joint entropy and CT entropy correlation with Hif1-alpha expression remained statistically significant (Ï = â0.60 and Ï = â0.50, respectively).Conclusions: CT texture joint entropy and CT entropy were associated with Hif1-alpha expression in HNSCC and might be able to reflect hypoxic areas in this entity
Hyperspectral Imaging (HSI)âA New Tool to Estimate the Perfusion of Upper Abdominal Organs during Pancreatoduodenectomy
Hyperspectral imaging (HSI) in abdominal surgery is a new non-invasive tool for the assessment of the perfusion and oxygenation of various tissues and organs. Its benefit in pancreatic surgery is still unknown. The aim of this study was to evaluate the key impact of using HSI during pancreatoduodenectomy (PD). In total, 20 consecutive patients were included. HSI was recorded during surgery as part of a pilot study approved by the local Ethics Committee. Data were collected prospectively with the TIVITAÂź Tissue System. Intraoperative HS images were recorded before and after gastroduodenal artery (GDA) clamping. We detected four patients with celiac artery stenosis (CAS) caused by a median arcuate ligament (MAL). In two of these patients, a reduction in liver oxygenation (StO2) was discovered 15 and 30 min after GDA clamping. The MAL was divided in these patients. HSI showed an improvement of liver StO2 after MAL division (from 61% to 73%) in one of these two patients. There was no obvious decrease in liver StO2 in the other two patients with CAS. HSI, as a non-invasive procedure, could be helpful in evaluating liver and gastric perfusion during PD, which might assist surgeons in choosing the best surgical approach and in improving patientsâ outcomes
ESID: A Visual Analytics Tool to Epidemiological Emergencies
Visual analysis tools can help illustrate the spread of infectious diseases
and enable informed decisions on epidemiology and public health issues. To
create visualisation tools that are intuitive, easy to use, and effective in
communicating information, continued research and development focusing on
user-centric and methodological design models is extremely important. As a
contribution to this topic, this paper presents the design and development of
the visual analytics application ESID (Epidemiological Scenarios for Infectious
Diseases). The goal of ESID is to provide a platform for rapid assessment of
the most effective interventions for infectious disease control. ESID provides
spatial-temporal analysis, forecasting, comparison of simulations, interactive
filters, and accessibility options. In its current form, it shows the
simulations of a hybrid graph-equation-based model as introduced in for
infection control. The model can be stratified for different age groups and
takes into account the properties of the infectious disease as well as human
mobility and contact behaviour.Comment: 6 pages, 5 images and 1 table, Eurovis workshop on visual analytics
(EuroVA) 202
ESID: Exploring the Design and Development of a Visual Analytics Tool for Epidemiological Emergencies
Visual analytics tools can help illustrate the spread of infectious diseases and enable informed decisions on epidemiological and public
health issues. To create visualisation tools that are intuitive, easy to
use, and effective in communicating information, continued research
and development focusing on user-centric and methodological design models is extremely important. As a contribution to this topic,
this paper presents the design and development process of the visual
analytics application ESID (Epidemiological Scenarios for Infectious Diseases). ESID is a visual analytics tool aimed at projecting
the future developments of infectious disease spread using reported
and simulated data based on sound mathematical-epidemiological
models. The development process involved a collaborative and
participatory design approach with project partners from diverse
scientific fields. The findings from these studies, along with the
guidelines derived from them, played a pivotal role in shaping the
visualisation tool
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